action.yml

name: Set up Rust and LLVM for Windows
description: >-
  Install the pinned Rust toolchain with Windows cross-compile targets and
  a version of LLVM whose libclang is loadable by bindgen.

inputs:
  arch:
    description: CPU architecture (x64, Win32, arm64)
    required: true

runs:
  using: composite
  steps:
    - uses: dtolnay/rust-toolchain@1.91.1
      with:
        targets: i686-pc-windows-msvc,x86_64-pc-windows-msvc,aarch64-pc-windows-msvc
    # LIBCLANG_PATH must be set explicitly so the vcxproj uses the LLVM we
    # install here rather than the VS-bundled LLVM whose clang headers have
    # AVX intrinsic bugs.  The values are hardcoded literals (no attacker-
    # controlled input), so the GITHUB_ENV writes are safe.
    - name: Install LLVM for bindgen
      if: inputs.arch != 'arm64'
      shell: cmd
      run: | # zizmor: ignore[github-env]
        choco install llvm --allow-downgrade --no-progress --version 21.1.0
        if not exist "C:\Program Files\LLVM\bin\libclang.dll" exit /b 1
        echo LIBCLANG_PATH=C:\Program Files\LLVM\bin>> "%GITHUB_ENV%"
    # Chocolatey's LLVM package only ships x64 binaries, which an ARM64-native
    # cargo process cannot load.  Install the official ARM64 build directly.
    - name: Install LLVM for bindgen (ARM64)
      if: inputs.arch == 'arm64'
      shell: pwsh
      run: | # zizmor: ignore[github-env]
        $installer = Join-Path $env:RUNNER_TEMP 'LLVM-21.1.0-woa64.exe'
        Invoke-WebRequest 'https://github.com/llvm/llvm-project/releases/download/llvmorg-21.1.0/LLVM-21.1.0-woa64.exe' -OutFile $installer
        Start-Process -Wait -FilePath $installer -ArgumentList '/S','/D=C:\Program Files\LLVM'
        if (!(Test-Path 'C:\Program Files\LLVM\bin\libclang.dll')) { exit 1 }
        echo "LIBCLANG_PATH=C:\Program Files\LLVM\bin" >> $env:GITHUB_ENV